Method for determining simultaneously th molecular weight and the Mark-Houwink coefficients for arylene siloxane polymer by using GPC and intrinsic viscosity data were deve-lopped. Porous silica beads column with efficiency of more than 4200-5500 plates per metre
was used. The polydispersity index of polymers were found to be 2. The molecular weight distribution becomes narrower and the molecular weight is lowered after milling.